Re: McKee/King Family, Alabama/ Texas

How would one go about verifying Marriage information without spending money on Ancestry.com or some of the others. I am using Familysearch alot, but there is not sufficient information to corroborate my hunch like I want? I suspect that John C. McKey married his cousin Mary J. mcKey 2/9/1873. Familysearch only gives me John McKey and Mary J. McKery but not enough re parents for example to make me feel completely comfortable with it.